Replacing hoses and mechanical fuel pump on my 1985 v8 5.0 trans am 305. And noticed in one of the hoses, there’s a metal ball inside, what is it for? Is it supposed to be in there? Is there a specific place on the hose it should be?

 

:shrug:

That's a new one on me. Looks kinda like it could be a check ball.

Which hose is this? What fuel system & engine did the car originally have?

 

it’s a 1985 v8 5.0 trans am 305, carbureted. It’s one of the two hoses connected to the mechanical fuel pump

 

My guess is that somebody put that in the return line in an attempt to get more fuel to the carb.

 

Probably had the wrong 2 port fuel pump on there at one time (in/out) and they plugged the return.
It should have a 3 port pump on there (in, out. & return.)

 

is this a good idea? And how does the ball not move around inside?

 

No, not a good idea.
These cars typically run hot causing vapor lock in the fuel line. This is made even worse if you run ethanol containing fuel. GM provided a return line is to prevent / reduce this problem.
Of course you'll need to verify that this is indeed the fuel tank return line before connecting it to anything.
Your pictures don't show where it was originally connected to or the new or old fuel pumps that are in question.

 

If that's what it is, just a ball of some sort jammed into the return line (the smaller rubber one at the fuel pump), and that line doesn't have a hookup at the pump, then it's some form of alternate socio-economic engineering, and needs to be done away with.

Put the right pump on the car as described and replace that little short section of rubber hose with good quality 5/16" or 8mm fuel hose. Make sure it's REALLY "fuel hose".

 

I would beg to differ. Recall that one cannot have their cake, with frosting, and also consume it. We can't blame ethanol for everything wrong with the world. Gasoline (naptha-benzene mixtures) can have a vapor point of 42°F (for the benzene fraction) whereas ethanol (corn alcohol) has a vapor point of 59°. Also consider that It takes 186 BTUs to evaporate a pound of typical gasoline, while it takes 395 BTUs to evaporate a pound of ethanol (both at STP). That means that gasoline will explode into vapor a with a lot less input heat energy (almost half) at a lot lower temperature than ethanol, and ethanol can be added to reduce the vapor pressure of gasoline.

Further consider the fact that we often blame ethanol for hard starting in colder temperatures, since evaporation requires a lot more heat than gasoline. This is also evidenced by E-85 engines running a lot cooler intake temperatures than gasoline engines.

You can't have it both ways.

Absolutely. That return fuel line was intended to keep liquid fuel moving through the system and reduce the heat buildup in the supply line. It will work without the return line, but certainly not as intended. The Powertrain boys and girls didn't change the design just because they had a lot of surplus steel tubing lying around.

 

I suspect that we may all be interpreting this incorrectly. The situation could simply be that the person working on this previously wanted the T/A to have more ***** than the typical LG4, and could prove that it did photographically.

 

40 years experience in the carbureted automotive world has made certain things clear to me, of course anyone is free to believe what they want.

Ethanol blended fuel will boil at a lower temp.
After shutdown, ethanol blended fuel can boil over in the carb bowl flooding the intake manifold.
Ethanol blended fuel will evaporate out of a carb bowl within days.
Those problems are exacerbated in hot weather.

You pay less for Ethanol fuel due to government subsidies, but you also get less MPG and will fill up more often.

 

There is little doubt that (in a given engine) ethanol will produce less energy per gallon than gasoline, just as kerosene/diesel will produce less energy than gasoline in an engine designed for gasoline. I did a casual study and experiment for over a year with one vehicle dedicated as the mule, and quantified the drop in mileage and determined that there are other ramifications as well. Evaporation wasn't one of them, due to the mule having a functional evap system and being EFI.